Numerical prediction of off-design performance for a Power-to-Gas system coupled with renewables

In this study, the off-design performance of a Power-to-Gas process are predicted by means of a developed calculation model, implemented in commercial tool environments. With the aim to evaluate the behaviour of the several components in off-design conditions, specific calculation models have been integrated in the whole system model. Then, starting from a real wind production profile, four configurations of the Power-to-Gas system have been analysed, evaluating the annual operating time of the integrated Power-to-Gas/wind systems. In addition, in order to assess the cost effectiveness of the technology, a preliminary economic analysis has been performed. The results highlight that the most performant configuration is the one at ambient pressure, with the co-electrolyzer and the high temperature methanation section operating at the same temperature, showing a methane production of 184 ton/year and an overall efficiency of about 75%. At the current technology readiness level, the economic competitiveness of the process is strongly affected by the synthetic natural gas sell price.